Snap fastener

ABSTRACT

The present invention relates generally to one-piece fasteners of the type having a central longitudinal aperture for a worksupporting screw member and adapted to be snapped into association with a noncircular workpiece aperture. The embodiment of the invention disclosed herein includes an elongate, substantially rigid or firm shank section having a longitudinal screw-accommodating aperture and laterally flexible shank sections superimposing the opposite sides of the rigid shank section. As the fastener is snapped into position within a work aperture, these flexible shank sections yield inwardly to facilitate initial insertion, peripheral shoulders intermediate the extremities of the flexible shank sections automatically flex outwardly as an incident to the movement of the shank sections for securing the fastener against axial movement in one direction and other shoulder means secure the fastener against movement in the opposite direction.

United States Patent [72] Inventor Julian V. Fisher Carpentersville,Ill. [21] Appl.N 855,107 {22] Filed Sept.4, 1969 Patented Apr. 13, 1971[73] Assignee Illinois Tool Works Inc.

ChicagoJll.

[54] SNAPFASTENER 11 Claims, 12 Drawing Figs.

[52] U.S.Cl 24/73, 85/80,151/4l.75, 248/27 [51] lnt.C1 ..F16b39/28,Fl6b13/06 FieldofSearch 85/70,72, l51/41.75; 248/27; 24/73 [56]References Cited UNITED STATES PATENTS 2,560,961 7/1951 Knohl /802,836,214 5/1958 Rapata..... 85/80 3,143,916 8/1964 Rice 85/71 3,415,15512/1968 Riddelletal 3,508,593 4/1970 Gill Primary Examiner-Donald A.Griffin Attomey0lson, Trexler, Wolters and Bushnell ABSTRACT: Thepresent invention relates generally to onepiece fasteners of the typehaving a central longitudinal aperture for a work-supporting screwmember and adapted to be snapped into association with a noncircularworkpiece aperture. The embodiment of the invention disclosed hereinincludes an elongate, substantially rigid or firm shank section PatentedApril 13, 1971 2 SheetsSheet 1 Patent ed April 13, 1971 3,574,899

2 Sheets-Sheet 2 SNAP FASTENER It is an important object of the presentinvention to provide a novel and improved one-piece fastener memberwhich may be snapped into a noncircular work aperture in readiness toaccommodate a complementary work-supporting screw member.

More specifically, the present invention contemplates an improvedone-piece fastener of the type referred to above which will withstandrelatively heavy loads to which a screw member carried thereby may besubjected.

The present invention contemplates a fastener as set forth above whereinnovel means is incorporated to facilitate axial insertion and subsequentautomatic interlocking of the fastener within an apertured workpiece orpanel. I

It is a further object of the present invention to provide a relativelysimple snapin-type fastener which may be produced by practicingconventional plastic molding methods, thereby enabling the fastener tobe produced at minimum manufacturing costs.

The foregoing and other objects and advantages will be more apparentfrom the following detailed description when considered in connectionwith the accompanying drawing, wherein:

FIG. 1 is a perspective view of a fastener of the type contemplated bythe present invention shown in operative association with a frame forsupporting an automobile headlight;

FIG. 2 is an enlarged fragmentary vertical sectional view takensubstantially along the line 2-2 of FIG. 1;

FIG. 3 is a horizontal sectional view taken substantially along the line3-3 of FIG. 2;

FIG. 4 is a transverse sectional view taken substantially along the line4-4 of FIG. 2;

FIG. 5 is a perspective view of the fastener illustrated in FIGS. 1-4inclusive, detached from the work supporting screw member;

FIG. 6 is a side elevational view disclosing the fastener during itsinitial collapsed insertion within a work aperture;

FIG. 7 is a horizontal sectional view taken substantially along the line7-7 of FIG. 2 to illustrate the fastener when finally inserted withinthe work aperture;

FIG. 8 is a perspective view of a one-piece plastic fastener of modifieddesign;

FIG. 9 is an elevational view disclosing the fastener of FIG. 8associated with a supporting screw member;

FIG. 10 is a view similar to FIG. 9 showing the one piece plasticfastener member in section and also in operative association with anapertured workpiece;

FIG. 11 is an elevational view of the fastener ta'ken substantiallyalong the line 11-11 of FIG. 10; and

FIG. 12 is a transverse sectional view taken substantially along theline 12-12 of FIG. 10.

Referring to the drawing more in detail, wherein like numerals have beenemployed to designate similar parts throughout the various figures, itwill be seen that one embodiment of the fastener contemplated by thepresent invention is designated generally by the numeral 10. Thefastener 10 is in the nature of a shank member which includes a centralrelatively rigid, elongate shank section 12. It will be noted that theshank section 12 is of polygonal cross section and is provided with acentral aperture 14 for accommodating a work supporting screw member 16.Projecting laterally from opposite sides of the shank section 12 at oneextremity thereof are oppositely disposed shoulder members 18 adapted toengage one surface of a workpiece or lamp supporting frame member 20.

Attention is now directed to laterally flexible elongate shank sections22 superimposing opposite sides of shank section 12 and spaced therefromby elongate recesses 24. Each of the laterally flexible shank sections22 is integrally joined with the opposite extremities of the relativelyrigid shank section 12 as clearly shown in the drawing. Each of thelaterally flexible shank sections 22 carry shoulders 26. 'l'hcseshoulders 26 are spaced axially front and disposed at 90" with respectto the previously mentioned shoulder 18. Thus the shoulders 26 areadapted to interlock with the opposite side of said workpiece. Thecross-sectional shape of the combined shank sections 12 and 22 ispolygonal and it will be noted that the peripheral surfaces defined bythe entering extremity of the shank sections 22 is of reduced crosssection to facilitate initial insertion of the fastener within a workaperture.

To illustrate one practical application or environment in which thefastener of the preset application has proven very satisfactory, FIGS.13 inclusive show the fastener in association with an automobileheadlamp support. The previously mentioned workpiece or frame member 20carries a plurality of circumferentially spaced fasteners 10. The outeror headed extremity of the screw member 16 associated with each fasteneris received by an opening or slot 28, FIG. 1, of a headlamp supportingframe 30. The headlamp is indicated generally by the numeral 32.

The fastener or shank member 10 is initially inserted within the workaperture in the manner shown in FIG. 6. The work aperture is preferablynoncircular and is complementary to the cross-sectional shape of thefastener 10. Initial insertion of the fastener causes the shoulder 26 toshift radially inwardly and upon completion of insertion, automaticallyto spring outwardly into interlocking relation with a marginal surfacearea adjacent the work aperture. In this position, the relatively fixedshoulders 18 cooperate to engage the opposite surface of the workpieceand thereby secure the fastener against axial dislodgement. The screwmember 16 inserted within the aperture 10 may be longitudinally adjustedto properly position the headlamp supporting frame 30. In some instancesit may be preferable to permit the screw member to form its own threadwithin the plastic fastener member 10 and in other instances it may bedesirable to provide preformed screw accommodating thread convolutionswithin the longitudinal aperture 14. In each instance it is essential toinsure a firm frictional fit between the thread convolutions of thescrew and the complementary thread convolutions within thelongitudinally apertured shank section 12. As the screw 16 is tightenedthe shoulders 26 are brought into impingement with the adjacent surfacearea of the workpiece 20. It has been found desirable to form theshoulder 26 in the manner illustrated in FIG. 5. In this connection itwill be noted that the shoulders 26 are preferably formed by twoslightly inclined shoulder surfaces which meet at a common work-engagingapex. By this construction any slight misalignment of the apertures 28of the frame 30 and the aperture 14 in the fastener 10 will not affectthe firm clamping fit of the fastener within its supporting workpiece orframe 20.

In FIGS. 8-12 inclusive, a modified form of fastener contemplated by thepresent invention is designated generally by the numeral 10a. Like thefastener 10 previously described the fastener 10a is in the nature of ashank member which includes a central, relatively rigid or firm elongateshank section 12a. The shank section 12a is provided with a centralaperture for accommodating a work supporting screw member 160.Projecting laterally from opposite sides of the shank section 12a at oneextremity thereof are oppositely disposed flexible arm members 18a. Thefree extremities of these arms 18a provide abutments for yieldinglyengaging one side of a worksheet or panel member 20a. The freeextremities of the arms 18a have the same function as the previouslydescribed shoulder 18 disclosed in FIGS. 17 inclusive.

The fastener member 10a is also provided with laterally flexibleelongate sections 22a. The provision of elongate recesses 240 permitsufficient collapsing of the shank sections 220 to facilitate axialinsertion of the fastener similarly to the fastener 10 as shown in FIG.6. Each of the laterally flexible shank sections 22a is integrallyjoined with the opposite extremities of the relatively rigid shanksection 12a and is provided with shoulders 26a which function similarlyto the previously described shoulders 26.

As the fastener is telescopically associated with a complementaryaperture in the workpiece 20a the advancing free extremities of theabutment arms 180 are ultimately brought into contact with one side ofthe work surface, and continued axial shifting of the fastener willresult in the shoulders 26a engaging the opposite side of the workpieceas clearly shown in FIG. 10. Thus the flexible arms 18a serve tocontinually urge the shoulders 26a into engagement with the workpiece,thereby assuring firm positioning of the fastener within the workpiece.It should also be understood that the shank sections 12a and 22a incombined cross section present an outer periphery of noncircular, orpolygonal, shape. The work aperture has a shape which is complementaryto the cross-sectional shape of the fastener. In the previouslydescribed fastener 10, the shoulders 26 and the shoulders 18 aredisposed at 90 with respect to each other, whereas in the fastener ajust described, the shoulders 26a and the shoulders provided at the freeextremity of the flexible arms 18a are positioned on the same side ofthe fastener. The fastener 100 may be used as a lamp support like thefastener 10, but obviously may be used in other applications where aworkpiece is provided with a suitable work accommodating aperture.

From the foregoing it will be apparent that the present inventioncontemplates the provision of a very simple yet practical and sturdyfastener of one-piece construction. Multipiece fasteners which haveheretofore been relatively expensive to produce do not have the grippingor holding firmness of the fastener contemplated by the presentinvention. By having the elongate, central shank section 12, sufficientthread engagement between the fastener and the screw member is assuredto withstand relatively high, longitudinal stresses experienced by thecomplementary screw member 16. AlSOythC structural design of thefastener assures effective resistance to substantial lateral forces towhich the screw member may be subjected. By having the elongate,laterally flexible shank sections integrally secured at oppositeextremities to the central, relatively rigid shank section 12, therequired flexibility of the sections 22 is assured without the potentialhazard of misalignment of said sections as might occur in instanceswhere one extremity of the section or arm is free. As previously stated,the fastener contemplated hereby may be produced at a minimum cost bypracticing conventional plastic molding methods.

lclaim:

l. A one-piece plastic snapin-type fastener for application to anapertured workpiece including an elongate, substantially rigid shanksection having a central longitudinal screw accommodating aperture,longitudinal, laterally flexible shank sections superimposing andnormally spaced from opposite sides of said rigid shank section, each ofsaid laterally flexible sections being integrally connected at opposedextremities to said rigid section, said shank sections in combined crosssection presenting an outer periphery of noncircular shape defining across-sectional area which is reduced toward the entering extremity ofthe fastener to facilitate initial insertion thereof within acomplementary work aperture, peripheral shoulder means intermediate theextremities of said flexible shank sections and adapted to shiftradially inwardly upon initial insertion within a workpiece aperture andautomatically to spring outwardly into interlocking relation with amarginal surface area adjacent said aperture when insertion iscompleted, and second shoulder means spaced axially from said firstshoulder means toward the trailing end of the fastener for interlockingwith the opposite marginal work surface area.

2. A one-piece plastic snapin-type fastener as set forth in claim 1,wherein the oppositely disposed peripheral surfaces defined by thelaterally flexible shank sections are inclined from the vicinity of theperipheral shoulder means thereof toward the entering extremity tofacilitate initial insertion within a work aperture.

3. A one-piece plastic snapin-type fastener as set forth in claim 1,wherein the peripheral shoulder means associated with the flexible shanksections are disposed at 90 with respect to the second shoulder meansspaced axially therefrom.

4. A one-piece plastic snapin-type fastener as set forth in claim I,wherein the second shoulder means extends radially outwardly fromopposite peripheral surfaces of the substantially rigid shank section.

5. A one-piece plastic snapin-type fastener as set forth in claim 4,wherein the oppositely disposed peripheral surfaces of the substantiallyrigid shank section from which the second shoulder means extend aresubstantially parallel.

6. A one-piece plastic snapin-type fastener as set forth in claim 4,wherein the oppositely disposed peripheral surfaces of the substantiallyrigid shank section from which the second shoulder means extend areseparated from each other by a distance substantially equal to the widthof the flexible shank sections.

7. A one-piece plastic snapin-type fastener as set forth in claim 1,wherein the peripheral surfaces defined by the laterally flexible shanksections are inclined toward each other in the vicinity of the shouldermeans thereof, and the width of said laterally flexible shank sectionsis unifomt throughout substantially the entire axial extent thereof.

8. A one-piece plastic snapin-type fastener as set forth in claim 7,wherein the oppositely disposed edges of the flexible shank members andthe adjacent peripheral surfaces of the rigid shank member arepositioned within a common plane.

9. A one-piece plastic snapin-type fastener as set forth in claim 1,wherein the second shoulder means is axially yieldable.

10. A one-piece plastic snapin-type fastener as set forth in claim 1,wherein the second shoulder means includes oppositely disposed,laterally flexible arms, the free extremities of which providework-engaging surface areas.

11. A one-piece plastic snapin-type fastener as set forth in claim 1,wherein the first and second shoulder means includes a pair of axiallyspaced shoulder members on one side of the fastener and a pair ofoppositely disposed shoulder members on the opposite side of thefastener.

1. A one-piece plastic snapin-type fastener for application to anapertured workpiece including an elongate, substantially rigid shanksection having a central longitudinal screw accommodating aperture,longitudinal, laterally flexible shank sections superimposing andnormally spaced from opposite sides of said rigid shank section, each ofsaid laterally flexible sections being integrally connected at opposedextremities to said rigid section, said shank sections in combined crosssection presenting an outer periphery of noncircular shape defining acrosssectional area which is reduced toward the entering extremity ofthe fastener to facilitate initial insertion thereof within acomplementary work aperture, peripheral shoulder means intermediate theextremities of said flexible shank sections and adapted to shiftradially inwardly upon initial insertion within a workpiece aperture andautomatically to spring outwardly into interlocking relation with amarginal surface area adjacent said aperture when insertion iscompleted, and second shoulder means spaced axially from said firstshoulder means toward the trailing end of the fastener for interlockingwith the opposite marginal work surface area.
 2. A one-piece plasticsnapin-type fastener as set forth in claim 1, wherein the oppositelydisposed peripheral surfaces defined by the laterally flexible shanksections are inclined from the vicinity of the peripheral shoulder meansthereof toward the entering extremity to facilitate initial insertionwithin a work aperture.
 3. A one-piece plastic snapin-type fastener asset forth in claim 1, wherein the peripheral shoulder means associatedwith the flexible shank sections are disposed at 90* with respect to thesecond shoulder means spaced axially therefrom.
 4. A one-piece plasticsnapin-type fastener as set forth in claim 1, wherein the secondshoulder means extends radially outwardly from opposite peripheralsurfaces of the substantially rigid shank section.
 5. A one-pieceplastic snapin-type fastener as set forth in claim 4, wherein theoppositely disposed peripheral surfaces of the substantially rigid shanksection from which the second shoulder means extend are substantiallyparallel.
 6. A one-piece plastic snapin-type fastener as set forth inclaim 4, wherein the oppositely disposed peripheral surfaces of thesubstantially rigid shank section from which the second shoulder meansextend are separated from each other by a distance substantially equalto the width of the flexible shank sections.
 7. A one-piece plasticsnapin-type fastener as set forth in claim 1, wherein the peripheralsurfaces defined by the laterally flexible shank sections are inclinedtoward each other in the vicinity of the shoulder means thereof, and thewidth of said laterally flexible shank sections is uniform throughoutsubstantially the entire axial extent thereof.
 8. A one-piece plasticsnapin-type fastener as set forth in claim 7, wherein the oppositelydisposed edges of the flexible shank members and the adjacent peripheralsurfaces of the rigid shank member are positioned within a common plane.9. A one-piece plastic snapin-type fastener as set forth in claim 1,wherein the second shoulder means is axially yieldable.
 10. A one-pieceplastic snapin-type fastener as set forth in claim 1, wherein the secondshoulder means includes oppositely disposed, laterally flexible arms,the free extremities of which provide work-engaging surface areas.
 11. Aone-piece plastic snapin-type fastener as set forth in claim 1, whereinthe first and second shoulder means includes a pair oF axially spacedshoulder members on one side of the fastener and a pair of oppositelydisposed shoulder members on the opposite side of the fastener.